Blade assembly



Sept. 21, 1954 H. E. M CRERY BLADE ASSEMBLY 3 Sheets$heet 1 Filed June3, 1948 -nga Sept. 21, 1954 H. E. M CRER-Y 2,689,507

BLADE ASSEMBLY Filed June 3, 1948 3 Sheets-Sheet 2 Sept. 21, 1954 FiledJune 3, 1948 H. E. M CRERY BLADE ASSEMBLY 3 Sheets-Sheet 3 I N VENTORATTORNEY Patented Sept. 21, 1954 BLADE ASSEMBLY Harold E. McCrery,Dayton, Ohio, assignor to Master Vibrator Company, Dayton, Ohio, acorporation of Ohio Application June 3, 1948, Serial No. 30,869

3 Claims.

This invention pertains to rotary power driven surfacing implements, andmore particularly to a blade assembly for use in such implements.

While for illustrative purposes the invention is herein shown anddescribed as embodied in a concrete .troweling machine or float forfinishing concrete surfaces and hard or mastic toppings for concretesub-bases, such as shown and claimed in my copending companionapplication, Serial No. 681,771, filed July 6, 1946, now matured intoLetters Patent No. 2,594,331, issued April 29, 1952, it is notnecessarily limited to such a machine for use.

The blade assembly forming the subject matter hereof permits the rotarypower driven apparatus with which they are used to be easily and quicklyconverted from a floating operation to a finishing operation, andrepresents a modification of the double blade assembly shown and claimedin my above-identified copending application.

The object of the invention is to improve the construction as well asthe means and mode of operation of rotary surface treating apparatus,

whereby it may not only be economically constructed, but will be moreeflicient in use, uniform in action, having a minimum number of workingparts and be unlikely to get out of repair.

A further objectof the inventionis to provide. a dual purpose blade,which may be used for both floating and finishing a surface without thenecessity of reversing such blade.

.A further object of the invention is to provide a surfacing bladehavinga pairof angularly disposed working surfaces, which surfaces maybe brought into working engagement with "the surface being treated byrotation of the blade about its pivotal mounting. a

A further object of the invention is to minimize the cost of suchblades, and simultaneously there- With minimize the change-over time,thereby providing a more eflicient and economical assembly.

A further objectof the invention is to provide a blade assembly whichmay be reversed upon its mounting while remaining in its original 'planeto present a new working surface upon wear of the original surface. 7 l

A further object of the invention is-to provide a blade assemblyembodying the advantageous structural features, the inherent meritoriouscharacteristics and the mode of operation herein set forth, or theirequivalents.

With the above primary and other incidental objects in view as will morefully appear in the specification, the invention intendedto be protectedby Letters Patent consists of the features of construction, the partsand combinations thereof, and the mode of operation, as hereinafterdescribed or illustrated in the accompanying drawings, or theirequivalents.

In the accompanying drawings, wherein is shown the preferred butobviously not necessarily the only form of embodiment of the invention,

Fig. 1 is a perspective view of a power driven,

rotary concrete finishing machine embodying the present invention.

Fig. 2 is a side view of the blade assembly removed from the finishingmachine.

Fig. 3 is a top view of the blade assembly per se, removed from itsmounting member.

Fig. 4 is an end view of the blade assembly in cooperation with theadjusting spider.

Fig. 5 is a fragmentary perspective view of the end of the bladeassembly when installed in the finishing machine.

Figs. 6 to 9, inclusive, are diagrammatic views showing variousoperating positions of the blade assembly. 1

Fig. 10 is a bottom plan view of the sweep control spider.

Fig. 11 is a detail showing of the sweep adjustmg means.

Like parts are indicated by similar characters of reference throughoutthe several views.

The present invention is a further development of those shown in myabove-identified copending application, the copending application ofHarold S. Boulton. Serial No. 721,574, filed January 11, 1947, nowmatured into Letters Patent No. 2,605,683, issued August 5, 1952, andanother copending application of mine, Serial No. 735,627, filed March19, 1947, to all of which cross reference is made, pertinent portionsthereof being shown and described herein for illustrative purposes only,but which per se, form no part of the present invention.

Referring to the accompanying drawings, the rotary surfacing machine inFig. 1, comprises a rotary base I from which radiate a plurality ofrotatably adjustable sweeps 22, surrounded by a guard ring 3 upon whichthe outer ends of the sweeps 2 are pivoted. Located in axial relationabove the revoluble base I is a gear housing 4 surmounted by a drivingmotor 5. The motor shown in Fig. l is a conventional explosive engine orhydrocarbon motor. An electric motor may be substituted for theexplosive engine 5. A driving pulley 6 of the motor, of whatever type,is connected by a V belt with a driven pulley 8 of the gear drivingmechanism within the housing 4. Ahandle 9 extends upwardly and radiallyfrom 3 the housing 4 for controlling and guiding the machine. Manuallyoperated control devices It mounted on the handle 9 within easy reach ofthe operator, are connected through the handle shaft with the actuatingmotor 5.

The power transmission, driving and adjusting features of the instantmachine are substantially those of my Patent No. 2,594,331, to whichreference is made. In brief, the means for adjusting the sweeps orblades about their oscillatory axes comprise a spider ll journaled uponthe central supporting member immediately above the base I, for limitedrelative oscillatory movement. The radial arms of the spider extend intooverhanging relation with the periphery of the base I and have in theirunder sides pockets or recesses into which project the. ends of rockarms 12 fast upon sweep shafts l3. By rotativel-y adjusting the spiderH, the rock arms l2 can be minutely adjusted simultaneously to slightlyrock the shaft It and with them the work blades to correspondingly varytheir pitch.

The spider II is rotatably adjusted relative to the base I by a handwheel M the shaft l lof which is threadedly supported within the base 1for longitudinal motion relative thereto. The end of the shaft [4 hasthrust engagement with a lever M within the base i, the opposite end ofthe lever projecting above the base I into thrust engagement with one ofthe radial arms H of the spider H.

The instant sweeps comprise a blade supporting angle bar l ihaving alaterally projecting bottom flange [5 to the inner end of which iswelded a short rectangular bar IE, which extend beyond the angle bar asthe cylindrical trunnion or sweep shaft i3. The rock arm i2 is welded tothe rectangular portion l6 of the shaft. At the opposite end of theangle bar Hi there is welded in axial alignment with the trunnion IS arectangular collar ll within which trunnion studs l8 welded to thesurrounding guard ring 3- are engageable.

The vertical portion of the angle bar M is disposed substantiallycoincident with the radii of the axis about which the sweeps rotate. At-

. tached to the flange if) of the angle bar" M- is a rectangular bar it,to which in turn is attached a channel member is carried by the bladeassembly 21-2-2.

As shown in Fig. 3, a pair of channels 2i] are secured to the larger orfloat blade 2| in equally spaced relation on opposite sides of thecenter line thereof. Only one of said channels are used at a time, butthe other channel is-assembled to the blade so that the blade may bereversed in its own plane and the second channel mountedonthe bar is topresent a new and unused contact area in engagement with the concretebeing worked. The opposite areas 23 are slightly inclined relative tothe main area of the blade, such inclination serving the dual purpose ofpreventing digging of the concrete surface being worked, and alsoproviding means for mounting the second of finishing blade 22 on thefloat blade 2i with the contact areas of thetwo blades being indivergent, angular relation one withthe other.

A series of equally spaced holes 2-4 are provided in the inclined edgeareas 23 of the float blade 2| by means of which the finishing blade 22is mounted on the float blade.

Mounted on the trailing edge of the float blade 21 is a somewhat smallerfinish blade 22, one edge of which has a series of holes thereincorresponding to the holes 24 in the float blade. Overlying the finishblade 22 is a backing or stiffening strip 26, the float blade 2|, thefinish blade 22 and the strip 26 being fixedly secured together by bolts21. The finish blade 22 is slightly inclined relative to the float blade2| and is not. in contact with the concrete surface during the floatingoperation as shown in Fig. 4.

The finish blade 22 is also symmetrical and may be turned upside downupon excessive wear of" the lower surface, thereby providing a new andunworn surface for further productive work. Upon change of the floatblade by use of the other channel 20,. the finish blade 22 may besecured to the opposite edge of the float blade, and Work continued.Thus, both blades are so constructed that double wear may be obtainedtherefrom before it becomes necessary to completely replace the bladeassembly.

The medial line of the finish blade 22' is like the medial line of thefloat blade 21, offset relative to the oscillatory axis of thesweepassembly;

In operation the machine is initially set with the float blade 2| in asubstantially horizontalposition as shown in full lines in Fig. 4. Forsome type of surfacing the floating operation is best performed with thefloat blade 2 l in aslightly inclined position, i. e., with the leadingedge thereof (to the left of Fig; 4) slightly elevatedin relation to theworking surface substantially as shown in Fig. '7. Whether in slightlyinclined or substantially horizontal position, the finish blade 22carried by the float blade '21 is sopositioned as" to be' in upwardlyinclined spaced" relation with the working surface. The mount-- ing ofthe finis blade 22 upon the inclined trailing edge 23 of the float blade21 provides for maintenance of the finish blade in inoperative position"during periods of use of the float blade 21'.

To change the machine from a floating toa finishing operation, it isonly' necessary to adjust the hand wheel il to further oscillatethesweep assembly about its oscillatory axis. By

so doing, the sweep assembly is brought intothe finishing position,shownin dotted lines in Fig. 4', whereby the finish blade 2-2 is broughtinto operative position and the float blade 2| is placed in inoperativeposition.

The change from floating to finishing is thereby greatly simplifiedsince the necessity of completely reversing the sweep assembly iscompletely eliminated; Both the finish blade 22' and. the float blade 2|areso related that eithermay be brought into operative positionbyaslight adjustment of the hand wheel M By reducing the distancebetween the mount-- i'ng channel 20' and the trailing edge of the floatblade 2|, flexibility of the blade is reduced, although not eliminated.A relatively stiff float blade has been found to be highly advantageousin the working. of cementitious surfaces. Upon movement of the finishblade. 22: into; operative position, however, the distance betweenthemounting channel 20 and the trailing edge of the blade is greatlyincreased, which permits greater flexing of the blade assembly duringthe finishing operation. Increased flexibility the finishing operationhas been found to be of advantage in that it produces a better surfacein less time. The backing strip 26 prevents ex c'essive flexing of theblade assembly through the joint area, and confines-"the flexing" to theassemtial area of the blade assembly, namely in the "flnish blade 22. la

The backing strip 26 also serves to reduce the flexing of the floatblade 2| while in use, thus assisting minimization of flexing in theblade.

To compensate for any inequalities in the assembly ofthe sweep units, anadjustable thrust member 28is engaged in the upstanding rock arm [2, thecap 29 of which is engageable within the recesses in the adjustingspider II. By movement of the thrust member 28 relative to the rock armI 2, each sweep assembly may be adjusted individually into correspondingplanes so that upon adjustment of the hand wheel I4 each sweep assemblywill assume a corresponding position in relation to the work surface.

The present construction provides what is in effect a single bladehaving a pair of working surfaces divergently inclined one relative tothe other, which surfaces may be optionally selected for operation tothe exclusion of the other surface. Each of the pair of work surfacesmay be easily brought into operative position by a slight adjustment ofthe hand wheel I4 without necessttating removal of the guard ring 3,change of blades, or disturbance to the adjusting mechanism. The overallweight of the sweep assembly is greatly reduced, while providing a moreefficient and advantageous structure, especially one in which the bladesmay be easily interchanged or reversed to permit the maximum use thereofbefore replacement.

It has been found beneficial on certain types of concrete to use thesurfacin blade in an intermediate position, i. e., with a portion ofboth the float blade 2| and finish blade 22 in operative engagement withthe surface being worked. In such position the blade has spaced contactwith the surface coincident with the heel or trailing edge of the floatblade and the trailing edge of the finish blade.

Examples of various blade positions are diagrammatically shown in Figs.6 to 9, inclusive. Fig. 6 shows the initial position with the floatblade 2| in substantially horizontal position contacting the worksurface throughout its entire area. Fig. 7 shows the first stage ofadjustment after the initial floating operation. The float blade 2| isinclined slightly and the finish blade 22 is lowered somewhat toward thework surface. Several different positions of adjustment intermediate thepositions of Figs. 6 and 8 may be used sequentially, or any one desiredposition may be utilized for performing this step in the surfacingoperation.

Fig. 8 shows the intermediate position wherein both the float and finishblade are in working contact with the concrete surface. As is showntherein, the blade assembly has operative engagement with the worksurface at relatively spaced points producing a double troweling actionduring one pass over the work surface. The inclined area 23 of the floatblade is in engagement with the work surface along its trailing edge,while the trailing edge of the finish blade 22 is also in engagementwith the surface being worked. The offset in the assembly resulting fromthe overlapped engagement of the finish and float blades permits thesimultaneous engagement of the two blades with the work surface atrelatively spaced points. This same result may be achieved in a singlepiece blade by forming a slight offset therein intermediate the twopoints of desired contact.

Fig. 9 shows the final or finish position of the blade assembly in whichonly the trailing edge of the finish blade 22 is in engagement with thework surface to complete the final or finishing operation thereon. l V

From the above description it will be apparent that there is thusprovided a device of the character described possessing the particularfeatures of advantage before enumerated as desirable, but whichobviously is susceptible of modification in its form, proportions,detail construction and ar rangementof parts without departing from theprinciple involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the means and construction herein disclosedcomprise but one of several modes of putting the invention into effect.

Having thus described my invention, I claim:

1. A sweep assembly for a surfacing machine, having a revolvingplurality of surfacing sweeps, including an oscillatory blade supportingmember, a rotatably mounted adjusting member carried by the machine andengageable with a portion of the blade supporting member to oscillatesaid member upon rotation of the adjusting member relative to themachine, means for varying the angular position of the supporting memberrelative to the adjusting member, and a duofunctional blade assemblymounted upon the bottom of said supporting member including a floatblade, the longitudinal axis of which is in relatively spaced relationwith the supporting member ahead of such member, upwardly inclinedmarginal areas thereon, a finish blade detachably secured to thetrailing one of said inclined marginal areas of the float blade, thefinish blade being disposed in inclined divergent relation with thefloat blade, and a backing member overlying the joint between the finishand float blades and extending in overlapping relation with each of saidblades for engagement therewith under pressure, the construction andarrangement being such that flexing of the float blade while inoperative position is minimized and flexing of the finish blade whenbrought into operative position by movement of the adjusting member isfacilitated while maintaining minimum flexibility in the float blade.

2. A sweep assembly for a surfacing machine, having a revolvingplurality of surfacing sweeps, including an oscillatory blade supportingmember, a rotatably mounted adjusting member carried by the machine andengageable with a portion of the blade supporting member to oscillatesaid member upon rotation of the adjusting member relative to themachine, means for varying the angular position of the supporting memberrelative to the adjusting member, and a duofunctional blade assemblymounted upon the bottom of said supporting member including a blademember having a pair of optionally usable working surfaces disposed ininclined divergent relation one to the other, a reinforcing memberoverlapping the juncture between the inclined working surfaces andengaged therewith under pressure, and means for detachably securing theblade member to the supporting member with the longitudinal axes of bothof said working surfaces on opposite sides of the supporting member.

3;, trowel-mg machinefem working; cement? tious surfaces, comprising. a.rotatable blade can'- rien, a multipurpose tnoweling: bl'adehaving asubstantially rectangular floating portion and a substantiallyrectangularportion upwardiy inclined from the trailing edge of saidfloating; portion, said blade'bei'ng mounted on said" blade barrier withthe longitudinal marginsof said blade portions parallel thereto, andmeans. ion oscil ating said: carrier about its axis for selectimeengagement at eithe oi th bl de ment ons with the cementitious surface.

References (ii-ted in. the= filje. of this patent,

5 UNITED STATES. PATENTS umbe a e Dat 21,198,974 Pi1ant. A913. 30,19402,2 43 Baily -r t Sept. 9', 19 11 10 277,389 Eonway Mar; 24 13942:

